A genuinely deserving Nobel laureate and a real provocateur, Dario Fo, has died at 90. No doubt the Nobel jury was influenced by his politics, as it often is, but there's no serious question of his literary importance.

Dario Fo, the Italian playwright, director and performer whose scathingly satirical work earned him both praise and condemnation, as well as the 1997 Nobel Prize in Literature, died on Thursday in Milan. He was 90. His death was confirmed by his Italian publisher, Chiarelettere.

Mr. Fo wrote more than 80 plays, many of them in collaboration with his wife, Franca Rame, who died in 2013, and his work was translated into dozens of languages. He was best known for two works: “Accidental Death of an Anarchist” (1970), a play based on the case of an Italian railroad worker who was either thrown or fell from the upper story of a Milan police station while being questioned on suspicion of terrorism; and his one-man show “Mistero Buffo” (“Comic Mystery”), written in 1969 and frequently revised and updated in the decades that followed, taking wild comic aim at politics and especially religion.

After a 1977 version of “Mistero Buffo” was broadcast in Italy, the Vatican denounced it as “the most blasphemous show in the history of television.” The church’s attitude toward Mr. Fo had not mellowed a generation later, when he was awarded the Nobel. “Giving the prize to someone who is also the author of questionable works is beyond imagination,” the Vatican newspaper L’Osservatore Romano said.

Many critics felt differently. “Imagine a cross between Bertolt Brecht and Lenny Bruce and you may begin to have an idea of the scope of Fo’s anarchic art,” Mel Gussow wrote in The New York Times in 1983.

Basing their art on the tradition of the medieval jester and the improvisation techniques of commedia dell’arte, Mr. Fo and Ms. Rame thrilled, dismayed and angered audiences around the world. Together they staged thousands of performances, in conventional theaters, factories occupied by striking workers, university sit-ins, city parks, prisons and even deconsecrated churches. “We’ve had to endure abuse, assaults by the police, insults from the right-thinking and violence,” Mr. Fo said in his Nobel lecture.

The worst episode occurred in 1973 — after a Fo play criticizing the police was presented in Milan — when his wife was kidnapped, tortured and raped by a fascist group later found to have links to members of the carabinieri, the Italian federal police. But Mr. Fo and Ms. Rame riled opponents across the political spectrum.

In 1968, Mr. Fo became persona non grata in much of Communist Europe after he withdrew all rights to the performance of his plays in Czechoslovakia to protest the Soviet-led invasion that toppled the reform Communist government there. He and his wife were also repeatedly denied entry into the United States because of their ties to the Italian Communist Party. The couple finally received a brief waiver for the 1984 Broadway opening of “Accidental Death of an Anarchist.” Mr. Fo attributed the State Department’s change of heart to the intervention of President Ronald Reagan, a former actor. It was, Mr. Fo said dryly, “the gesture of a colleague.” Two years later Mr. Fo and his wife were again allowed to visit, this time to make their joint American debut as performers.

Mr. Fo was nevertheless often critical of American military and economic might and what he saw as its deleterious impact on the world. Days after the terrorist attacks of Sept. 11, 2001, he drew considerable attention, and condemnation for a widely circulated email in which he bluntly wrote: “The great speculators wallow in an economy that every year kills tens of millions of people with poverty — so what is 20,000 dead in New York? Regardless of who carried out the massacre, this violence is the legitimate daughter of the culture of violence, hunger and inhumane exploitation.”

Dario Fo was born on March 24, 1926, in the small northern Italian town of Sangiano. His father, Felice, was a railway stationmaster, socialist and amateur actor, and his mother, Pina Rota, wrote an acclaimed autobiography, “Il Paese delle Rane” (“The Country of Frogs”), about her peasant family.

As a child, Dario would travel in a horse-drawn wagon around the countryside peddling vegetables with his maternal grandfather, who attracted customers by telling them stories spliced with news accounts and anecdotes about local events. Mr. Fo would later do much the same thing onstage.

Another important influence was the tragicomic narrative tradition of the glass artisans near his native town. “They were the old storytellers, the master glassblowers who taught me and other children the craftsmanship, the art, of spinning fantastic yarns,” Mr. Fo recalled in his Nobel speech. “We would listen to them, bursting with laughter — laughter that would stick in our throats as the tragic allusion that surmounted each sarcasm would dawn on us.”

In 1940, Mr. Fo moved to Milan to study at the Brera Fine Arts Academy. During World War II, he was conscripted into the army but fled and went into hiding with the help of his parents, who were active in the resistance. His father helped Italian Jews and British prisoners of war escape into Switzerland by train, while his mother tended to wounded partisans who fought against Mussolini and against the Nazi occupation forces after Mussolini was deposed in 1943.

After the war, Mr. Fo became a stage designer and was swept up by the piccolo teatri (small theaters) movement, which emphasized improvised monologues on social issues presented at affordable prices. He met Ms. Rame in 1951 while they were acting in a Milanese theater troupe. They married three years later. Their son, Jacopo, born in 1955, became a left-wing political activist and a prolific writer, best known for his 12-volume “Encyclopedia of Sublime Sex.” Mr. Fo is survived by his son.

In the 1950s, Mr. Fo staged productions at the Piccolo Teatro in Milan, though many of them were shut down because of opposition from politicians and the church authorities. He also began writing screenplays for Italian films and occasionally acting in them. In 1962, Mr. Fo was hired by the Italian state television network, RAI, to write, direct and host “Canzonissima,” a long-running variety show that had a different host every year. Working with Ms. Rame, he wrote sketches that introduced biting social commentary to the show.

His version of “Canzonissima” was extremely popular, but not with everyone. Sketches that addressed worker safety and other serious issues were censored. After a sketch about the Mafia killing of a journalist was aired — and condemned by an Italian senator, who told Parliament that “the honor of the Sicilian people is insulted by the claim that there exists a criminal organization called the Mafia” — Mr. Fo and Ms. Rame received death threats and were given police protection. A final confrontation over censorship led them to walk off the show, and they were barred from the network for 15 years.

Their work became even more politically radical in the 1970s, when they formed the theater group Collettivo Teatrale La Comune. The company presented the premiere of “Accidental Death of an Anarchist” in 1970 and followed it with Mr. Fo’s “Fedayin” (1971), a play about the Palestinian-Israeli conflict that included members of the Palestine Liberation Organization in the cast. In 1974 they staged “We Won’t Pay! We Won’t Pay!” (1974), a satire in which housewives, angered by rising prices, steal food from a supermarket and set off events that bring Milan to a standstill.

His work brought Mr. Fo increasing fame worldwide over the next two decades, but even so the Nobel Prize came as a surprise to him and his supporters; in their view his eclectic, unorthodox art and his reputation as an onstage jester seemed far removed from the more conventional oeuvre of other literature laureates. But Mr. Fo was grateful, telling the Swedish Academy, “Yours is an act of courage that borders on provocation.”

Throughout his long career, Mr. Fo encouraged directors in Italy and around the world to tailor performances of his plays to local issues. “A theater, a literature, an artistic expression that does not speak for its own time,” he said in his Nobel lecture, “has no relevance.”